Worker uses magnifier as he checks ballot papers in Jakarta
A worker uses a magnifier as he checks ballot papers printed for upcoming presidential election at a factory in Jakarta, Indonesia January 20, 2019. Reuters

Indonesia's Constitutional Court is expected to issue a ruling on Thursday on a bid to change the country's voting system, an official said, a case that has sparked concern about a possible delay to an election just eight months away.

The case filed by several politicians, including a member of the ruling Democratic Party of Struggle Party (PDI-P) seeks a return of a closed ballot list system that was scrapped in 2008, where voters choose parties instead of local candidates.

Of the nine factions in parliament, eight have opposed changing the system, which they say would be regressive and undemocratic.

Some legal and political experts have warned the procedures

involved in changing the balloting so close to the February 2024 polls would make a delay possible.

"The possibility of an election delay is high if the ruling is a closed system," said Bivitri Susanti of Indonesia's Jentera school of law, adding the election commission would need time to implement the necessary changes.

Fajar Laksono, the court spokesperson, confirmed a decision on the voting system was expected on Thursday.

The election in the world's third largest democracy will choose a new legislature and president, with incumbent Joko Widodo, better known as Jokowi, due to reach the end of his second and final term next year.

The court case and talk of an election delay has added fuel to persistent speculation that allies of Jokowi want him to stay in power longer, a scenario he has officially rejected.

Those concerns are compounded by a series of unorthodox manoeuvres in recent months that some politicians see as possible attempts to disrupt and interfere in the electoral process.

A court in March ordered the election be delayed after an obscure, newly formed party said its registration had been unfairly rejected by the poll body. A higher court overruled that and Supreme Court has accepted the party's appeal.

Jokowi's opponents have also raised alarm over repeated legal efforts by his chief of staff, Moeldoko, to take over the leadership of Indonesia's biggest opposition party.

Jokowi for his part last week admitted to involvement in some behind the scenes "meddling" with parties and presidential candidates, in what he says is to ensure a smooth transition of power, adding that none of his moves would "tarnish democracy".

Some legal experts and analysts say that any postponement of the 2024 polls would require a revision of the elections law, which was not likely to win the required support in parliament.